Dental bridge.



Patented Feb. 8, 19H5.

TTI? l -Y v i WE.

GEORGE W. TODD, 0F OMAHA, NEBRASK.

DENTAL BRIDGE.

Specification of Letters Patent.

Patented rea. s, raie.

Application led April 24, 1915. Serial No. 23,575.

To all whom 'it may concern.'

Be it known that I, GEORGE W. TODD, a citizen of the United States,residing at Omaha, in the county of Douglas and State of Nebraska, haveinvented certain new and useful Improvements in Dental Bridges, of whichthe following is a specification.

n This invention relates to an improvement 1 n dental bridges, and hasfor one of its ob- ]ects to provide metallic clasps of such-form thatthey will present surfaces of greater area than ordinary for beingconnected when disposed side by side, so that the bridge may have lanadequate strength by using a limited quantity of metal.

Another object is to produce Ushaped, metallic clasps having braceebarsarranged to prevent spreading, and provided with parallel ridgesdisposed in a manner to adequately sustain stressesdirected'longitudinally of the teeth. f

The invention also has reference to the provision of porcelain teethofsuch form that they may be conveniently mounted upon or removed fromthe metallicclasps.'

While the invention is illustrated in connection with dental bridges,the metallic clasps and teeth may be used to advantage for dentalplates.

In the accompanying drawing which illustrates the invention, Figure 1 isa side View of a procelain tooth. Fig. 2 is a rear view of the same.Fig. 3 is a transverse section on line 3 3 of Fig. 1. Fig. 4 is an endor top plan view 'of ametallic clasp. Fig. 5 is a view in longitudinalsection of a metallic clasp on line 5 5 of Fig. 4:. Fig. 6 is a frontview of a bridge constructed in accordance with the invention. Fig. 7 isa rear view of the bridge shown in Fig. 6. Fig. 8 is a sectional View ofthe bridge on line 8 8 of Fig. 7. Fig. 9 illustrates a modied form ofthe invention, showing a side view of a tooth and clasp, parts beingbroken away and in section.

Referring now to the drawing, numerals 10 indicate teeth constructed ofporcelain or other suitable material, their bases a being ofconventional saddle-shape so that they will conform substantially to thesurface o'f the gums upon which they are to be normally seated, thefront part of each tooth preferably being of greater length than therear part as shown in the drawing. In each tooth a groove b is formed ineach of its sides midway between its front and back and extending nearto its top, a` second groove m being formed in its base opening on thegrooves b, and each tooth is provided with a recess cof substantiallysemicircular form extending longitudinally of the tooth from near itstop to open on its base, and which extends forwardly to open upon thegrooves b; and preferably grooves b are formed upwardly convergent fromthe base as best shown in Fig.v 1.

Numerals 11 indicate metallic holders or clasps each consisting of anattenuated, curved plate d substantially of U-shape in cross-section,each wing thereof, at its end, being provided with an inwardlyprojecting ridge e, the lower ends of said ridges being connected by atransversely disposed reinforcing strip f, each curved plate having aform corresponding to that of a recess o and the ridges and reinforcingstrip conforming respectively to the shape of the grooves and of atooth, and, when assembled, the metallic parts of the clasp which havebeen mentioned are adapted to substantially lill the grooves and recessVof a tooth.

'Io form the bridge shown in Figs. 6, 7, and 8, solder is employed forconnecting the clasps side by side, and the clasps may be soldered tothe crowns 12; and after the teeth have been mounted in the metallicclasps, the bridge will be complete.

The convergent form mentioned for grooves b is desired since thisfeature facilitates the mounting'of the teeth in the clasps after themetallic parts of the bridge have been prepared. Cement is preferablyemployed for connecting the procelain teeth with the clasps. On accountof the convergence mentioned for grooves b the stresses directedlongitudinally of the teeth will normally tend to press them inwardly ofand therefore to be firmly held by the clasps, the ridges e coperatingto advantage for sustaining the stresses, and strips f preventingspreading of the ridges e or sides of the clasps. In instances wheregold is employed the construction is of particular ad vantage since thestresses are directed endwise of the ridges and clasps, and therefore alesser quantitygof expensive metal than ordinary may be used.

According to theV described construction, the use of pins or lugs may bedispensed with and cement depended upon for connecting each'tooth withits clasp, and this so 9o 95 is an adequate holding means, especiallyfor the front teeth. By this construction any procelain tooth may bereadily removed from the`v bridge by a dentist by moving it outwardlyand parallel with ridges e; and a new tooth may be inserted by movingyit inwardly toward the base of the bridge and substantially parallelwith said ridges.

Fig. 9 illustrates the use of lugs or pins, all other parts being thesame as already described, and the use of'pins is not considered to be adeparture from the invention since they may be inserted after the teethhave been placed in the clasps, suitable apertures and lc being providedrespectively in the clasp and-the tooth, the pins m being used, ifdesired, for securing the molars or largerteeth to the clasps.

In devices for the purpose described, the combination of a plurality ofteeth each having grooves formed in lts sides between gagingrespectively in a recess and the first y named grooves of a tooth, saidreinforcing strip engaging in the second groove thereof. In testimonywhereof, ll have aixed my signature in presence of two witnesses.

GEORGE W. TODD. Witesses:

M A. STURGES, ARTHUR H. Smarts.

